GT.fmt_bytes

GT.fmt_bytes(
    self,
    columns=None,
    rows=None,
    standard='decimal',
    decimals=1,
    n_sigfig=None,
    drop_trailing_zeros=True,
    drop_trailing_dec_mark=True,
    use_seps=True,
    pattern='{x}',
    sep_mark=',',
    dec_mark='.',
    force_sign=False,
    incl_space=True,
    locale=None,
)

Format values as bytes.

With numeric values in a table, we can transform those to values of bytes with human readable units. The fmt_bytes() method allows for the formatting of byte sizes to either of two common representations: (1) with decimal units (powers of 1000, examples being "kB" and "MB"), and (2) with binary units (powers of 1024, examples being "KiB" and "MiB"). It is assumed the input numeric values represent the number of bytes and automatic truncation of values will occur. The numeric values will be scaled to be in the range of 1 to <1000 and then decorated with the correct unit symbol according to the standard chosen. For more control over the formatting of byte sizes, we can use the following options:

Parameters

columns : SelectExpr = None

The columns to target. Can either be a single column name or a series of column names provided in a list.

rows : int | list[int] | None = None

In conjunction with columns=, we can specify which of their rows should undergo formatting. The default is all rows, resulting in all rows in targeted columns being formatted. Alternatively, we can supply a list of row indices.

standard : str = 'decimal'

The form of expressing large byte sizes is divided between: (1) decimal units (powers of 1000; e.g., "kB" and "MB"), and (2) binary units (powers of 1024; e.g., "KiB" and "MiB"). The default is to use decimal units with the "decimal" option. The alternative is to use binary units with the "binary" option.

decimals : int = 1

This corresponds to the exact number of decimal places to use. A value such as 2.34 can, for example, be formatted with 0 decimal places and it would result in "2". With 4 decimal places, the formatted value becomes "2.3400". The trailing zeros can be removed with drop_trailing_zeros=True.

drop_trailing_zeros : bool = True

A boolean value that allows for removal of trailing zeros (those redundant zeros after the decimal mark).

drop_trailing_dec_mark : bool = True

A boolean value that determines whether decimal marks should always appear even if there are no decimal digits to display after formatting (e.g., 23 becomes 23. if False). By default trailing decimal marks are not shown.

use_seps : bool = True

The use_seps option allows for the use of digit group separators. The type of digit group separator is set by sep_mark and overridden if a locale ID is provided to locale. This setting is True by default.

pattern : str = '{x}'

A formatting pattern that allows for decoration of the formatted value. The formatted value is represented by the {x} (which can be used multiple times, if needed) and all other characters will be interpreted as string literals.

sep_mark : str = ','

The string to use as a separator between groups of digits. For example, using sep_mark="," with a value of 1000 would result in a formatted value of "1,000". This argument is ignored if a locale is supplied (i.e., is not None).

dec_mark : str = '.'

The string to be used as the decimal mark. For example, using dec_mark="," with the value 0.152 would result in a formatted value of "0,152"). This argument is ignored if a locale is supplied (i.e., is not None).

force_sign : bool = False

Should the positive sign be shown for positive values (effectively showing a sign for all values except zero)? If so, use True for this option. The default is False, where only negative numbers will display a minus sign.

incl_space : bool = True

An option for whether to include a space between the value and the currency symbol. The default is to not introduce a space character.

locale : str | None = None

An optional locale identifier that can be used for formatting values according the locale’s rules. Examples include "en" for English (United States) and "fr" for French (France).

Returns

: GT

The GT object is returned. This is the same object that the method is called on so that we can facilitate method chaining.

Adapting output to a specific locale

This formatting method can adapt outputs according to a provided locale value. Examples include "en" for English (United States) and "fr" for French (France). The use of a valid locale ID here means separator and decimal marks will be correct for the given locale. Should any values be provided in sep_mark or dec_mark, they will be overridden by the locale’s preferred values.

Note that a locale value provided here will override any global locale setting performed in GT()’s own locale argument (it is settable there as a value received by all other methods that have a locale argument).

Examples

Let’s use a single column from the exibble dataset and create a new table. We’ll format the num column to display as byte sizes in the decimal standard through use of the fmt_bytes() method.

from great_tables import GT, exibble

(
    GT(exibble[["num"]])
    .fmt_bytes(columns="num", standard="decimal")
)
num
0 B
2 B
33 B
444 B
5.5 kB
777 kB
8.9 MB

See Also

The functional version of this method, val_fmt_bytes(), allows you to format a single numerical value (or a list of them).